There are a variety of robots programmed to clean and mop floors. These robots may traverse a room in a random or pseudo-random manner pre-programmed in the robot navigation system. A pump on the robot is used to squirt cleaning agent or other fluid on the floor as the robot traverses the space. The pump is powered using a battery that is carried onboard the robot and recharged when not in use at a docking station, for example. Wires running to the battery provide power to the pump. Depending on the configuration of the robot, the electrical wiring may further include plugs to remove the pump along with a cleaning attachment. As such, use a pump adds to the complexity, weight, and power consumption of the robot without adding to its reliability. There is therefore a need for a mechanism to passively dispense cleaning fluid in a controlled manner without an electronically controlled pump.